Devices, systems and methods for carbon dioxide angiography

ABSTRACT

Disclosed herein are various embodiments of devices, systems and methods for the delivery of carbon dioxide (CO 2 ) as a contrast agent for angiography. The CO 2  delivery device can include a syringe and a shuttle valve assembly in fluid communication with the syringe, such that the shuttle valve can be disposed in a first position to pressurize the syringe with CO 2 , and a second position to deliver a bolus of CO 2  to a subject.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.61/594,740 filed on Feb. 3, 2012, titled “Devices, Systems and Methodsfor Carbon Dioxide Angiography,” which is hereby incorporated byreference in its entirety.

TECHNICAL FIELD

The present disclosure relates generally to medical devices. Inparticular, the present disclosure relates to devices, systems andmethods for vascular interventions using carbon dioxide (CO₂) as acontrast agent. Certain embodiments relate, more particularly, todevices, systems and methods for delivering CO₂ to a subject for use asa contrast agent for angiography.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments disclosed herein will become more fully apparent fromthe following description and appended claims, taken in conjunction withthe accompanying drawings. These drawings depict only typicalembodiments, which will be described with additional specificity anddetail through use of the accompanying drawings in which:

FIG. 1 is a schematic diagram of an exemplary carbon dioxide (CO₂)angiography system, illustrating a CO₂ supply assembly 140, CO₂ deliverydevice 130 and a connection line 110.

FIG. 2 is a rear perspective view of one embodiment of a CO₂ deliverydevice 130 that includes a shuttle valve assembly 100 connected to andin fluid communication with a syringe 120, which may be used by themethods and systems disclosed herein.

FIG. 3 is a side view of the CO₂ delivery device 130 of FIG. 2.

FIG. 4 is a cross sectional view of the CO₂ delivery device 130 of FIG.3. This cross sectional view illustrates the CO₂ delivery device 130 ina first position, such that the chamber 122 of the syringe 120 is influid communication with the first port 102 of the shuttle valveassembly 100.

FIG. 5 is an enlarged, partially cut-away cross sectional view of ashuttle valve assembly 100 connected to a syringe 120. This enlargedcross sectional view illustrates the CO₂ delivery device 130 in a secondposition, such that the chamber 122 of the syringe 120 is in fluidcommunication with the second port 104 of the shuttle valve assembly100.

FIG. 6 is a front perspective view of another embodiment of a CO₂delivery device 230, illustrating an alternative design of the syringe220.

FIG. 7 is a side view of the CO₂ delivery device 230 of FIG. 6.

FIG. 8 is a front view of one end of the CO₂ delivery device 230illustrated in FIG. 6.

FIG. 9 is a cross sectional view of the CO₂ delivery device 230 of FIG.7. This cross sectional view illustrates the CO₂ delivery device 230 ina first position, such that the chamber 222 of the syringe 220 is influid communication with the first port 202 of the shuttle valveassembly 200.

FIG. 10 is an enlarged, partially cut away cross sectional view of ashuttle valve assembly 200 connected to a syringe 220. This enlargedcross sectional view illustrates the CO₂ delivery device 230 in a secondposition, such that the chamber 222 of the syringe 220 is in fluidcommunication with the second port 204 of the shuttle valve assembly200.

FIG. 11 is a front perspective view of one embodiment of a CO₂ deliverydevice 330. This front perspective view illustrates finger-receivingportions 314 that are attached to the exterior cylindrical surface ofthe chamber 322.

FIG. 12 is a top view of the CO₂ delivery device 330 of FIG. 11.

FIG. 13 is a side view of the CO₂ delivery device 330 of FIG. 11.

FIG. 14 is a front view of one end of the CO₂ delivery device 330illustrated in FIG. 11.

FIG. 15 is a cross sectional view of the CO₂ delivery device 330 of FIG.13. This cross sectional view illustrates the CO₂ delivery device 330 ina first position, such that the chamber 322 of the syringe 320 is influid communication with the first port 302 of the shuttle valveassembly 300.

FIG. 16 is an enlarged, partially cut away cross sectional view of ashuttle valve assembly 300 connected to a syringe 320. This enlargedcross sectional view illustrates the CO₂ delivery device 330 in a secondposition, such that the chamber 322 of the syringe 320 is in fluidcommunication with the second port 304 of the shuttle valve assembly300.

FIG. 17 is a front perspective view of another embodiment of a CO₂delivery device 430, illustrating an alternative design of the shuttlevalve assembly 400.

FIG. 18 is an exploded view of the CO₂ delivery device 430 of FIG. 17.

FIG. 19 is a side view of the CO₂ delivery device 430 of FIG. 17.

FIG. 20 is a top view of one end of the CO₂ delivery device 430illustrated in FIG. 17.

FIG. 21 is a bottom perspective view of the valve block 401 of theshuttle valve assembly 400.

FIG. 22 is a cross sectional view of the CO₂ delivery device 430 of FIG.19. This cross sectional view illustrates the CO₂ delivery device 430 ina first position, such that the chamber 422 of the syringe 420 is influid communication with the first port 402 of the shuttle valveassembly 400.

FIG. 23 is an enlarged, partially cut away cross sectional view of ashuttle valve assembly 400 connected to a syringe 420. This enlargedcross sectional view illustrates the CO₂ delivery device 430 in a secondposition, such that the chamber 422 of the syringe 420 is in fluidcommunication with the second port 404 of the shuttle valve assembly400.

FIG. 24 is a rear perspective view of a CO₂ delivery device 530 with anintegrated CO₂ source 550. This rear perspective view illustrates a CO₂source 550 that is attached to the exterior cylindrical surface of thechamber 522 and connected first port 502 of the shuttle valve assembly500, such that the chamber 522 of the syringe 520 is in fluidcommunication with the first port 502 of the shuttle valve assembly 500and the CO₂ source 550.

FIG. 25 is a side view of the CO₂ delivery device 530 of FIG. 24.

FIG. 26 is a cross sectional view of the CO₂ delivery device 530 of FIG.25. This cross sectional view illustrates the CO₂ delivery device 530 ina first position, such that the chamber 522 of the syringe 520 is influid communication with the first port 502 of the shuttle valveassembly 500 and the CO₂ source 550.

FIG. 27 is an enlarged, partially cut away cross sectional view of theCO₂ delivery device 530 of FIG. 26 in a second position, such that thechamber 522 of the syringe 520 is in fluid communication with the secondport 504 of the shuttle valve assembly 500.

DETAILED DESCRIPTION

Traditionally, iodinated contrast agents (e.g., iohexol, iodixanol andiopromide) have typically been used for angiography. While iodinatedcontrast agents are generally harmless to most subjects, side effects,including anaphylactic reactions and contrast-induced nephropathy thatare associated with such contrast agents, still exist. Additionally,iodinated contrast agents may not be suitable for use in certainsubjects who are hypersensitive to iodinated contrast agents or whoserenal function is compromised. The use of CO₂ as an angiographiccontrast agent has increased because of its cost-effectiveness relativeto traditional contrast agents, and its use has not been found to beassociated with allergic reactions or nephrotoxicity. As will beappreciated, CO₂ may not be suitable for use as an arterial contrastagent above the diaphragm due to the risk of gas embolism of thecoronary, cerebral and spinal arteries. However, CO₂ may be used as acontrast agent in sites below the diaphragm or in the extremities forvarious types of angiography, including cholangiography, nephrography,gastrography and the like.

Devices, systems and methods for angiography using carbon dioxide (CO₂)as a contrast agent are described herein. The methods, systems anddevices disclosed are suited for delivering CO₂ to a subject for use asan angiographic contrast agent. The methods described herein includeusing a CO₂ delivery device to deliver CO₂ as an angiographic contrastagent. The devices described herein include CO₂ delivery devices thatare configured for one-handed operation and increased adjustability ofthe volume of CO₂ to be delivered to a subject.

For example, in certain embodiments, the CO₂ delivery device may includea shuttle valve assembly having a valve base that receives a valveblock. In such an embodiment, a biasing member may be disposed betweenthe valve block having an opening, and the valve base having a firstport and a second port. The shuttle valve assembly may include one ormore sealing members disposed between the valve block and the valvebase. The shuttle valve assembly may be connected to a syringe having achamber and a plunger.

When no force is applied to the valve block against the biasing member,the CO₂ delivery device maintains a first position, wherein the openingof the valve block is substantially aligned with the first port of thevalve base, while the second port of the valve base is isolated betweentwo sealing members. The first position allows the first port of theshuttle valve assembly to be in fluid communication with the chamber ofthe syringe, while the second port is isolated and/or closed from beingin fluid communication with the chamber of the syringe. In oneembodiment, the first port may be connected to at least one CO₂ source,such that the CO₂ source is in fluid communication with the chamber ofthe syringe. In such an embodiment, CO₂ may flow from the CO₂ source tofill the chamber of the syringe when the CO₂ delivery device ismaintained in the first position.

When a force is applied to the valve block against the biasing member,the CO₂ delivery device engages in a second position. In the secondposition, the opening of the valve block is substantially aligned withthe second port of the valve base. When engaged in the second position,the chamber of the syringe is in fluid communication with the secondport of the shuttle valve assembly, while the first port is isolatedand/or closed from being in fluid communication with the chamber of thesyringe. In one embodiment, the second port may be connected to orotherwise in fluid communication with a connection line suitable fordelivering CO₂ to a subject. In such an embodiment, CO₂ may be deliveredto the subject from the chamber of the syringe when the CO₂ deliverydevice is engaged in the second position.

In alternative embodiments, the CO₂ delivery device may include ashuttle valve assembly having a valve base that receives a valve block.In such an embodiment, a biasing member may be disposed between thevalve block having a first port and a second port, and the valve basehaving an opening. The shuttle valve assembly may be connected to asyringe having a chamber and a plunger.

When no force is applied to the valve block against the biasing member,the CO₂ delivery device maintains a first position, wherein the openingof the valve base is substantially aligned with the first port of thevalve block. The first position allows the chamber of the syringe to bein fluid communication with the first port of the shuttle valveassembly, while the second port is isolated and/or closed from being influid communication with the chamber of the syringe. In one embodiment,the first port may be connected to at least one CO₂ source, such thatthe CO₂ source is in fluid communication with the chamber of thesyringe. In such an embodiment, CO₂ may flow from the CO₂ source to fillthe chamber of the syringe when the CO₂ delivery device is maintained inthe first position.

When a force is applied to the valve block against the biasing member,the CO₂ delivery device engages in a second position. In the secondposition, the opening of the valve base is substantially aligned withthe second port of the valve block. When engaged in the second position,the chamber of the syringe is in fluid communication with the secondport, while the first port is isolated and/or closed from being in fluidcommunication with the chamber of the syringe. In one embodiment, thesecond port may be connected to or otherwise in fluid communication witha connection line suitable for delivering CO₂ to a subject. In such anembodiment, CO₂ may be delivered to the subject from the chamber of thesyringe when the CO₂ delivery device is engaged in the second position.

As will be appreciated, the configuration of the CO₂ delivery device maybe reversed, such that the first position is engaged when a force isapplied to the actuating member and/or valve block against the biasingmember, and the second position is engaged when the force is released.In one embodiment, to load the syringe chamber with CO₂, the firstposition may be engaged, such that the first port of the valve base andthe opening of the valve block are substantially aligned to allow thechamber to be loaded with CO₂, while the second port is isolated and/orclosed from being in fluid communication with the chamber of thesyringe. In one embodiment, the first position is engaged forapproximately five seconds, although this measurement is not intended tobe limiting. To deliver a bolus of CO₂ to the patient, the force may bereleased to engage the device in the second position, such that thesecond port of the valve base is substantially aligned with the openingof the valve block, while the first port is isolated and/or closed frombeing in fluid communication with the chamber of the syringe.

In another embodiment, to load the chamber of the syringe with CO₂, thefirst position may be engaged, such that the first port of the valveblock and the opening of the valve base are substantially aligned toallow the chamber to be loaded with CO₂, while the second port isisolated and/or closed from being in fluid communication with thechamber of the syringe. In one embodiment, the first position is engagedfor approximately five seconds, although this measurement is notintended to be limiting. To deliver a bolus of CO₂ to the patient, theforce may be released to engage the device in the second position, suchthat the second port of the valve block is substantially aligned withthe opening of the valve base, while the first port is isolated and/orclosed being in fluid communication with the chamber of the syringe.

The devices and systems, as described herein, may be configured so as toallow for single-handed operation of the CO₂ delivery devices to deliverone or more boli of CO₂ to a subject. The configuration of CO₂ deliverydevices described herein reduces or eliminates the need for dual-handedoperation of the CO₂ delivery devices to deliver one or more boli of CO₂to a subject. To deliver a bolus of CO₂ in accordance with the exemplarydevices and systems disclosed herein, a user can grasp or hold a CO₂delivery device in the first position with one hand and actuate thedevice with the same hand to engage the device in a second position, soas to deliver a bolus of CO₂ to a subject.

It will be readily understood with the aid of the present disclosurethat the components of the embodiments, as generally described andillustrated in the figures herein, could be arranged and designed in avariety of configurations. Thus, the following more detailed descriptionof various embodiments, as represented in the figures, is not intendedto limit the scope of the disclosure, but is merely representative ofvarious embodiments. While the various aspects of the embodiments arepresented in drawings, the drawings are not necessarily drawn to scaleunless specifically indicated.

FIG. 1 provides a schematic illustration of an embodiment of a systemsuited to the methods for delivering CO₂ as an angiographic contrastagent to a subject. Shown in FIG. 1 is a CO₂ supply assembly 140comprising a pressure regulator 142, a sterile filter 144, a CO₂ gassupply line 146 and a gas sensor 148. In some embodiments, the pressureregulator 142 maintains the pressure of the CO₂ being delivered from theCO₂ source 150 to the syringe 120 at approximately 1.3 atm above normalatmospheric pressure. As will be appreciated, a gas sensor 148 may beincluded in the CO₂ supply assembly 140 to ensure that the gas beingdelivered to the subject is CO₂ gas and not a gas other than CO₂. Insome embodiments, the gas sensor 148 may be included in the CO₂ supplyassembly 140 to ensure that the CO₂ gas being delivered to the subjectis not contaminated with a gas other than CO₂. In an embodiment, the gassensor 148 may be an O₂ gas sensor.

As illustrated in FIG. 1, the CO₂ gas supply line 146 of the CO₂ supplyassembly 140 may be coupled to a CO₂ delivery device 130, which includesa shuttle valve assembly 100 attached to a syringe 120. The shuttlevalve assembly 100 includes a valve base 116 that is connected orotherwise attached to a valve block 101. The shuttle valve assembly 100is attached to the syringe 120, such that the longitudinal axis of theshuttle valve assembly 100 is perpendicular to the longitudinal axis ofthe syringe 120. In some embodiments, as shown herein, the syringe 120includes a plunger 124 with threads 126 spirally disposed over thecylindrical surface of the plunger 124 and a chamber 122 configured toreceive the threaded plunger 124. The syringe 120 may be configured toinclude a thread-receiving member 128 at the base of the chamber 122 toretain the threaded plunger 124, so as to allow tunable adjustment ofthe volume of the chamber 122. In an alternative embodiment, the syringe120 may be configured to have a predetermined volume. In certainembodiments, the first port 102 and the second port 104 on the valvebase 116 may be coupled to a CO₂ gas supply line 146 and a connectionline 110, respectively. The connection line 110 may include an outlet112 for coupling to a catheter (not shown) for delivery of CO₂ to thepatient.

It will be appreciated by those of skill in the art having the benefitof this disclosure that this order may be modified. For example, the gassensor 148 may be positioned between the pressure regulator 142 and thesterile filter 144 and/or the CO₂ delivery system may be in accordancewith another embodiment disclosed herein. It can also be appreciatedthat the schematic illustration of the embodiment of the systemdescribed herein may be modified to include additional CO₂ sources 150,sterile filters 144, CO₂ gas supply lines 146 and/or gas sensors 148. Aswill be appreciated, the one or more gas sensors 148 may be integratedinto the CO₂ delivery device 130 and/or system. In certain embodiments,the one or more gas sensor 148 may be integrated with the shuttle valveassembly 100, the chamber 122, the plunger 124, the connection line 110,or other parts of the CO₂ delivery device 130 and/or system that may bedirectly or indirectly coupled to the subject, such that leaks and/orcompromised parts in the CO₂ delivery device 130 and/or system may bedetected or identified.

FIGS. 2-4 provide rear perspective, side, and cross sectional views ofan exemplary CO₂ delivery device 130 in the first position,respectively. Shown in FIGS. 2-4 is a CO₂ delivery device 130 having ashuttle valve assembly 100 and a syringe 120 in the first position.

As illustrated in this embodiment, the shuttle valve assembly 100 mayinclude a valve base 116 having a first port 102 and a second port 104,a valve block 101 having an opening 105, and a biasing member 106. Thevalve block 101 is connected to and substantially received by the valvebase 116, such that the longitudinal axes of the valve block 101 and thevalve base 116 are substantially collinear. As further illustrated inFIG. 4, the shuttle valve assembly 100 may include one or more circularsealing members 117. In some embodiments, the one or more circularsealing members 117 may be an o-ring. In an embodiment, the valve block101 is substantially received by the valve base 116, such that the oneor more circular sealing members 117 are disposed between the valveblock 101 and the valve base 116. The syringe 120 connected to theshuttle valve assembly 100 may include a chamber 122 and a plunger 124,wherein the chamber 122 is configured to receive the plunger 124. Asillustrated in FIGS. 2-4, the shuttle valve assembly 100 is connected tothe syringe 120, such that the longitudinal axis of the shuttle valveassembly 100 is substantially perpendicular to the longitudinal axis ofthe syringe 120. The first port 102 and the second port 104 may bepositioned substantially adjacent to each other and may protrude alongthe radius of the valve base 116, such that the longitudinal axes of thefirst port 102 and the second port 104 are substantially perpendicularto the longitudinal axis of the shuttle valve assembly 100. In someembodiments, the longitudinal axes of the first port 102 and the secondport 104 may be substantially collinear with the longitudinal axis ofthe syringe 120.

To maintain the CO₂ delivery device 130 in the first position, a biasingmember 106 may be disposed between the valve block 101 and the valvebase 116, such that the opening 105 of the valve block 101 issubstantially aligned with the first port 102, while the second port 104is isolated and/or closed from being in fluid communication with thechamber 122 of the syringe 120. In some embodiments, the second port 104may be isolated between two circular sealing members 117 when the CO₂delivery device 130 is maintained in the first position. Examples ofmechanisms suitable for use as a biasing member 106 include compressionsprings, volute springs, and the like. When the CO₂ delivery device 130is in the first position, the substantial alignment of the first port102 with the opening 105 of the valve block 101 allows the chamber 122of the syringe 120 to be in fluid communication with the first port 102,such that the first port 102 may be directly or indirectly coupled to aCO₂ source (as illustrated in FIG. 1) to load the chamber 122 of thesyringe 120 with CO₂.

FIG. 5 provides an enlarged cross sectional view of a CO₂ deliverydevice 130 illustrated in FIGS. 2-4, wherein the CO₂ delivery device 130is engaged in the second position. To engage the CO₂ delivery device 130in the second position, a force (illustrated as F₁ in FIG. 4) may beapplied to the valve block 101 against the biasing member 106, such thatthe valve block 101 slides toward the biasing member 106. When engagedin the second position, the opening 105 of the valve block 101 issubstantially aligned with the second port 104 of the valve base 116,while the first port 102 of the valve base 116 is isolated and/or closedfrom being in fluid communication with the chamber 122 of the syringe120. In an embodiment, the first port 102 of the valve base 116 may beisolated between two circular sealing members 117 when the CO₂ deliverydevice 130 is engaged in the second position. As illustrated in FIG. 5,the chamber 122 of the syringe 120 is in fluid communication with thesecond port 104 of the shuttle valve assembly 100. The second port 104may be coupled to a connection line (not shown) suitable for deliveringCO₂ to a subject. When the CO₂ delivery device 130 is engaged in thesecond position, the CO₂ in the chamber 122 of the syringe 120 may bedelivered to the subject.

As illustrated herein, the syringe 120 may be configured to include athreaded plunger 124 and a chamber 122 suitable for receiving a threadedplunger 124. In one embodiment, the chamber 122 may include athread-receiving member 128 that is configured to receive the threadedplunger 124, so as to allow for tunable adjustment of the volume of thechamber 122. As will be appreciated, a threaded plunger 124 and achamber 122 configured to receive a threaded plunger 124 allows forincreased adjustability of the volume of CO₂ within the syringe 120, andallows the user greater control over the volume of CO₂ to beadministered to the subject. Furthermore, a threaded plunger 124 mayalso prevent a practitioner from inadvertently delivering an explosivebolus to a patient by translating the plunger too rapidly.

In an alternative embodiment, the syringe 120 may be configured to havea predetermined volume. The syringe 120 may be configured to hold avolume ranging from about 1 cc to about 200 cc, although these valuesare not intended to be limiting. In certain embodiments, the syringe 120may be configured to hold a volume ranging from about 1 cc to about 150cc, about 1 cc to about 100 cc, about 20 cc to about 100 cc, about 20 ccto about 80 cc, and about 20 cc to about 60 cc. As will be appreciated,these values may be tunably adjusted to accommodate greater or smallervolumes within the chamber 122 of the syringe 120. If desired, apractitioner may further or fully empty the chamber 122 of the syringe120 by actuating the plunger 124.

In accordance with the embodiment as provided herein, a user may holdthe CO₂ delivery device 130 single-handedly by grasping the outersurface of the syringe chamber 122, such that the shuttle valve assembly100 points away from the user, and the valve block 116 faces upward. Todeliver one or more boli of CO₂ using the CO₂ delivery device 130, auser may apply a force (illustrated as F₁ in FIG. 4) with their thumb tothe valve block 116 against the biasing member 106, so as to engage theCO₂ delivery device 130 in a second position.

FIGS. 6, 7 and 9 provide front perspective, side, and cross sectionalviews of an exemplary CO₂ delivery device 230, respectively. Shown inFIGS. 6, 7 and 9 is a CO₂ delivery device 230 having a shuttle valveassembly 200 and a syringe 220 in the first position.

The shuttle valve assembly 200 may include a valve base 216 having afirst port 202 and a second port 204, a valve block 201 having anopening 205, and a biasing member 206. The valve block 201 is connectedto and substantially received by the valve base 216, such that thelongitudinal axes of the valve block 201 and valve base 216 aresubstantially collinear. As further illustrated in FIG. 9, the shuttlevalve assembly 200 may include one or more circular sealing members 217.In an embodiment, the valve block 201 and the valve base 216 are bothsubstantially cylindrical. In some embodiments, the valve block 201 issubstantially received by the valve base 216, such that the one or morecircular sealing members 217 are disposed between the valve block 201and the valve base 216. The syringe 220 connected to the shuttle valveassembly 200 may include a chamber 222 and a plunger 224, wherein thechamber 222 is configured to receive the plunger 224. As illustrated inFIGS. 6, 7 and 9, the shuttle valve assembly 200 is connected to thesyringe 220, such that the longitudinal axis of the shuttle valveassembly 200 is substantially perpendicular to the longitudinal axis ofthe syringe 220. The syringe 220 may include a plunger 224 (that mayoptionally be threaded) and a chamber 222 configured to receive theplunger 224. In one embodiment, the syringe 220 may be configured tohave a predetermined volume. The first port 202 and the second port 204may be positioned substantially adjacent to each other and may protrudealong the radius of the valve base 216, such that the longitudinal axesof the first port 202 and the second port 204 are substantiallyperpendicular to the longitudinal axis of the shuttle valve assembly200. In certain embodiments, the longitudinal axes of the first port 202and the second port 204 may be substantially parallel to thelongitudinal axis of the syringe 220.

To maintain the CO₂ delivery device 230 in the first position, a biasingmember 206 may be disposed between the valve block 201 and the valvebase 216, such that the opening 205 of the valve block 201 issubstantially aligned with the first port 202, while the second port 204is isolated and/or closed from being in fluid communication with thechamber 222 of the syringe 220. In some embodiment, the second port 204of the valve base 216 may be isolated between two circular sealingmembers 217 when the CO₂ delivery device 230 is maintained in the firstposition. When maintained in the first position, the chamber 222 of thesyringe 220 is in fluid communication with the first port 202, such thatthe first port 202 may be directly or indirectly coupled to a CO₂ source(as illustrated in FIG. 1) to load the chamber 222 of the syringe 220with CO₂.

FIG. 8 provides a front view of one end of the exemplary CO₂ deliverydevice 230 of FIG. 6 in the first position. As shown in FIG. 8, thefirst port 202 and the second port 204 are positioned adjacent to eachother, such that both the first port 202 and the second port 204 areprotruding from the valve base 216 along the sagittal plane (indicatedas 9 in FIG. 8) of the CO₂ delivery device 230.

FIG. 10 provides an enlarged cross sectional view of the CO₂ deliverydevice 230 illustrated in FIGS. 6-9, wherein the CO₂ delivery device 230is engaged in the second position. To engage the CO₂ delivery device 230in the second position, a force (illustrated as F₁ in FIG. 9) may beapplied to the valve block 201 against the biasing member 206, such thatthe valve block 201 slides toward the biasing member 206. When engagedin the second position, the opening 205 of the valve block 201 issubstantially aligned with the second port 204 of the valve base 216,such that the chamber 222 of the syringe 220 is in fluid communicationwith the second port 204 of the shuttle valve assembly 200, while thefirst port 202 is isolated and/or closed from being in fluidcommunication with the chamber 222 of the syringe 220. In an embodiment,the first port 202 may be isolated between two circular sealing members217 when the CO₂ delivery device 230 is engaged in the second position.The second port 204 may be coupled to a connection line (not shown)suitable for delivering CO₂ to a subject. When the CO₂ delivery device230 is engaged in the second position, the CO₂ in the chamber 222 of thesyringe 220 may be delivered to the subject.

In accordance with the embodiment as provided herein, a user may holdthe CO₂ delivery device 230 single-handedly by grasping the outersurface of the syringe chamber 222, such that the shuttle valve assembly200 points away from the user and the valve block 216 faces upward. Todeliver one or more boli of CO₂ using the CO₂ delivery device 230, auser may apply a force (illustrated as F₁ in FIG. 9) with their thumb tothe valve block 216 against the biasing member 206, so as to engage theCO₂ delivery device 230 in a second position.

FIGS. 11-13 provide front perspective, top and side views, respectively,of an exemplary CO₂ delivery device 330 in the first position. Shown inFIGS. 11-13 is a CO₂ delivery device 330 that includes twofinger-receiving mechanisms 314 that are attached to the outer surfaceof the chamber 322 of the syringe 320.

The finger-receiving mechanisms 314 are configured such that a user mayhold the CO₂ delivery device 330 with one hand for single-handedoperation of the device 330. In one embodiment, both of thefinger-receiving mechanisms 314 are attached to syringe 320 on thecoronal plane of the CO₂ delivery device 330 and positioned adjacent tothe shuttle valve assembly 300. As illustrated in FIGS. 11-13, theshuttle valve assembly 300 is connected to the syringe 320, such thatthe longitudinal axis of the shuttle valve assembly 300 is collinearwith the longitudinal axis of the syringe 320. As described in previousembodiments, the syringe 320 may include a threaded plunger 324 and achamber 322 configured to receive the threaded plunger. In oneembodiment, the syringe 320 may be configured to have a predeterminedvolume. As will be appreciated, the actual volume dispensed to thesubject is dependent on the gas pressure and the predetermined volume ofthe syringe 320. In some embodiments, the practitioner may adjust thevolume of CO₂ delivered to the patient by adjusting the gas pressureand/or the predetermined volume of the syringe 320.

FIG. 14 provides a top view of one end of the CO₂ delivery device 330.As shown in FIG. 14, both of the finger-receiving mechanisms 314 areattached to the syringe 320 on the coronal plane of the CO₂ deliverydevice 330.

FIG. 15 illustrates a cross sectional view of the CO₂ delivery device330 in a first position. As shown in FIG. 15, the shuttle valve assembly300 may include one or more circular sealing members 317. In someembodiments, the valve block 301 is substantially received by the valvebase 316, such that the one or more circular sealing members 317 aredisposed between the valve block 301 and the valve base 316. To maintainthe CO₂ delivery device 330 in the first position, a biasing member 306may be disposed between the valve block 301 and the valve base such thatthe opening 305 of the valve block 301 is substantially aligned with thefirst port 302, while the second port 304 is isolated and/or closed frombeing in fluid communication with the chamber 322 of the syringe 320. Inan embodiment, the second port 304 may be isolated between two circularsealing member 317 when the CO₂ delivery device 330 is maintained in thefirst position. The substantial alignment of the first port 302 with theopening 305 of the valve block 301 allows the chamber 322 of the syringe320 to be in fluid communication with the first port 302, such that thefirst port 302 may be directly or indirectly coupled to a CO₂ source (asillustrated in FIG. 1) to load the chamber 322 of the syringe 320 withCO₂.

FIG. 16 illustrates an enlarged cross sectional view of the CO₂ deliverydevice 330 provided in FIGS. 11-15, wherein the CO₂ delivery device 330is engaged in a second position. To engage the CO₂ delivery device 330in the second position, a force (illustrated as F₁ in FIG. 15) may beapplied to the valve block 301 against the biasing member 306, such thatthe valve block 301 moves toward the biasing member 306. When the CO₂delivery device 330 is engaged in the second position, the opening 305of the valve block 301 is substantially aligned with the second port 304of the valve base 316, while the first port 302 is isolated and/orclosed from being in fluid communication with the chamber 322 of thesyringe 320. In an embodiment, the first port 302 is isolated betweentwo circular sealing members 317 when the CO₂ delivery device 330 isengaged in the second position. As shown in FIG. 16, the chamber 322 ofthe syringe 320 is in fluid communication with the second port 304 ofthe shuttle valve assembly 300. The second port 304 may be coupled to aconnection line (not shown) suitable for delivering CO₂ to a subject.When the CO₂ delivery device 330 is engaged in the second position, theCO₂ in the chamber 322 of the syringe 320 may be delivered to thesubject.

In accordance with the embodiment as illustrated herein, a user mayinsert their index finger into one finger-receiving mechanism 314 andtheir middle finger into the other finger-receiving mechanism 314. Todeliver one or more boli of CO₂ using the CO₂ delivery device 330, theuser may apply a force (illustrated as F₁ in FIG. 15) to the valve block301 using their thumb on the same hand as the index and middle fingersholding the finger-receiving mechanisms 314, so as to actuate theshuttle valve assembly 300 and engage the CO₂ delivery device 300 in thesecond position.

FIGS. 17, 19 and 22 provide front perspective, side, and cross sectionalviews, respectively, of an exemplary CO₂ delivery device 430 in thefirst position. Shown in FIGS. 17, 19 and 22 is a syringe 420 having achamber 422 and a plunger 424, and a non-cylindrical shuttle valveassembly 400 that includes an actuating member 408, a valve block 401,and a valve base 416. As further illustrated in FIG. 22, the valve block401 may include a first port 402 and a second port 404, and the valvebase 416 may include an opening 405. As shown in FIG. 22, thenon-cylindrical shuttle valve assembly 400 may also include a biasingmember 406, one or more circular sealing members 417 and an elongatedsealing member 419.

As illustrated herein, the valve block 401 may be configured to includea first port 402 and a second port 404, and the valve base 416 may beconfigured to include an opening 405. The valve block assembly 400 maybe configured such that the valve block 401 is slidably attached to thevalve base 416, such that a biasing member 406 may positioned betweenthe valve block 401 and the valve base 416 to maintain the CO₂ deliverydevice 430 in the first position. The valve base 416 may be hingeablyattached to an actuating member 408 that may be positioned adjacent tothe valve block 401. When the CO₂ delivery device 430 is maintained inthe first position, the opening 405 of the valve base 416 issubstantially aligned with the first port 402, while the second port 404is prevented from being in fluid communication with the chamber 422 ofthe syringe 420. In an embodiment, a circular sealing member 417 sealsaround the first port 402 when the first port 402 is substantiallyaligned with the opening 405, such that the second port 404 is not influid communication with the chamber 422 of the syringe 420 when the CO₂delivery device 430 is in the first position. In certain embodiments,the second port 404 is isolated between the elongated sealing member 419and the circular sealing member 417 sealing the first port 402 when theCO₂ delivery device 430 is in the first position. The substantialalignment of the first port 402 with the opening 405 of the valve base416 allows the chamber 422 of the syringe 420 to be in fluidcommunication with the first port 402, such that the first port 402 maybe directly or indirectly coupled to a CO₂ source (as illustrated inFIG. 1) to load the chamber 422 of the syringe 420 with CO₂. Asdescribed in previous embodiments, the syringe 420 may include a plunger424 (optionally threaded) and a chamber 422 configured to receive theplunger 424. In one embodiment, the syringe 420 may be configured tohave a predetermined volume.

FIG. 18 illustrates an exploded view of the CO₂ delivery device 430provided in FIGS. 17, 19 and 22. Shown in FIG. 18 is a syringe 420having a chamber 422 and a plunger 424, an actuating member 408, a valveblock 401 having a first port 402 and a second port 404, a valve base416, a biasing member 406, two circular sealing members 417 and anelongated sealing member 419.

FIG. 20 provides a top view of one end of the exemplary CO₂ deliverydevice 430 of FIG. 17 in the first position. As shown in FIG. 20, thelengths of the first port 402 and the second port 404 are seriallypositioned along the sagittal plane (indicated as 22 in FIG. 20) of thevalve block 401. The valve block 401 is slidably connected to the valvebase 416, such that the valve block 401 slides along an axis that issubstantially perpendicular to the longitudinal axis of the syringe 420.

FIG. 21 provides a bottom perspective view of the valve block 401 of theCO₂ delivery device 430. As illustrated in FIG. 21, the first port 402and the second port 404 may be positioned adjacent to each other alongthe sagittal plane (indicated as plane 22 in FIG. 20) of the valve block401.

FIG. 23 illustrates an enlarged cross sectional view of the CO₂ deliverydevice 430 provided in FIGS. 17-20 and 22, wherein the CO₂ deliverydevice 430 is engaged in a second position. To engage the CO₂ deliverydevice 430 in the second position, a force (illustrated as F₁ in FIG.19) may be applied to the actuating member 408 and/or the valve block401 against the biasing member 406, such that the valve block 401 slidesaway from the actuating member 408. When the CO₂ delivery device 430 isengaged in the second position, the second port 404 is substantiallyaligned with the opening 405 of the valve base 416, while the first port402 is prevented from being in fluid communication with the chamber 422of the syringe 420. In an embodiment, a circular sealing member 417seals around the second port 404 when the second port 404 issubstantially aligned with the opening 405, such that the first port 402is not in fluid communication with the chamber 422 of the syringe 420when the CO₂ delivery device 430 is in the second position. In certainembodiments, the first port 402 is isolated between the elongatedsealing member 419 and the circular sealing member 417 sealing thesecond port 404 when the CO₂ delivery device 430 is in the secondposition. When the CO₂ delivery device 430 is engaged in the secondposition, the chamber 422 of the syringe 420 is in fluid communicationwith the second port 404 of the shuttle valve assembly 400, such thatthe second port 404 may be coupled to a connection line (not shown) forthe delivery of CO₂ to a subject.

In accordance with the embodiment as provided herein, a user may holdthe CO₂ delivery device 430 single-handedly by grasping the outersurface of the syringe chamber 422, such that the shuttle valve assembly400 is pointing upward. To deliver one or more boli of CO₂ using the CO₂delivery device 430, a user may apply a force with their fingers or palmof their hand to the actuating member 408 and/or the valve block 416against the biasing member 406, so as to engage the CO₂ delivery device430 in a second position.

FIGS. 24-26 provide rear perspective, side and cross sectional views,respectively, of an exemplary CO₂ delivery device 530 in the firstposition. Shown in FIGS. 24-26 is an integrated CO₂ source 550,integrated CO₂ source 550 retaining member 551, a pressure regulator542, a syringe 520 having a chamber 522 and a plunger 524, a valve base516 having a first port 502 and a second port 504, and a valve block501. FIG. 26 further illustrates a biasing member 506, a plurality ofcircular sealing members 517, and a valve block 501 having an opening505.

As illustrated herein, a CO₂ source 550 may be integrated with the CO₂delivery device 530, such that the CO₂ source 550 is coupled to apressure regulator 542, which is coupled to the first port 502 of theshuttle valve assembly 500. Examples of CO₂ sources 550 suitable for usein this context include CO₂ cartridges and the like. In an embodiment,the CO₂ source 550 may be a disposable CO₂ cartridge. In anotherembodiment, the CO₂ source 550 may be a reusable and/or refillable CO₂cartridge. The CO₂ source 550 may be attached onto or integrated intothe CO₂ delivery device 530. In some embodiments, the CO₂ source 550 maybe attached to the chamber 522 of the syringe 520, such that the CO₂source 550 is aligned along the longitudinal axis of the syringe 520. Instill other embodiments, the CO₂ delivery device 530 may include a CO₂source 550 retaining member 551 to hold or secure the CO₂ source 550 inplace. As will be appreciated, an integrated CO₂ source 550 (e.g., CO₂cartridge) eliminates the need for a user to locate and connect a CO₂source 550 with the CO₂ delivery device 530. In addition, integrating aCO₂ source 550 into the CO₂ delivery device 530 reduces and/oreliminates the risk of accidental coupling to a source that iscontaminated or that contains a gas or fluid other than CO₂.

The shuttle valve assembly 500 may be connected to the syringe 520, suchthat the longitudinal axis of the shuttle valve assembly 500 isperpendicular to the longitudinal axis of the syringe 520. The shuttlevalve assembly 500 may include a valve base 516 having a first port 502and a second port 504, a valve block 501 having an opening 505, and abiasing member 506. The valve block 501 may be connected to andsubstantially received by the valve base 516, such that the longitudinalaxes of the valve block 501 and valve base 516 are substantiallycollinear. In an embodiment, the valve block 501 and the valve base 516may both be substantially cylindrical. In certain embodiments, the valveblock 501 may be substantially received by the valve base 516, such thata plurality of circular sealing members 517 are disposed between thevalve block 501 and the valve base 516. The first port 502 and thesecond port 504 may protrude from the valve base 516 along the radius ofthe valve base 516, such that the first port 502 is substantiallycontralateral to the second port 504 and the longitudinal axes of thefirst port 502 and the second port 504 are substantially perpendicularto the longitudinal axis of the shuttle valve assembly. In certainembodiments, the longitudinal axes of the first port 502 and the secondport 504 may be substantially collinear with the longitudinal axis ofthe syringe 520. The syringe 520 connected to the shuttle valve assembly500 may include a chamber 522 and a plunger 524, wherein the chamber 522is configured to receive the plunger 524. As described in previousembodiments, the syringe 520 may include a plunger 524 having threads526 spirally disposed over the cylindrical surface of the plunger 524and a chamber 522 configured to receive the threaded plunger 524. In anembodiment, a thread-receiving member 528 may be used to allow forincremental adjustability of the volume within the chamber 522 using thethreaded plunger 524. In an alternative embodiment, the syringe 520 maybe configured to have a predetermined volume, or may include a plunger524 without threads 526.

When the CO₂ delivery device 530 is maintained in the first position,the opening to the first port 502 and the opening 505 of the valve block501 are aligned between two circular sealing members 517, such that theCO₂ source 550 and the first port 502 are in fluid communication withthe chamber 522 of the syringe 520, while the second port 504 isisolated and/or closed from being in fluid communication with thechamber 522 of the syringe 520. In some embodiments, the second port 504may be isolated between two circular sealing members 517 when the CO₂delivery device 130 is maintained in the first position.

FIG. 27 provides an enlarged cross sectional view of the CO₂ deliverydevice 530 illustrated in FIGS. 24-26, wherein the CO₂ delivery device530 is engaged in the second position. To engage the CO₂ delivery device530 in the second position, a force (illustrated as F₁ in FIG. 25) maybe applied to the valve block 501 against the biasing member 506, suchthat the valve block 501 slides toward the biasing member 506. When theCO₂ delivery device 530 is engaged in the second position, the secondport 504 of the valve base 516 is substantially aligned with the opening505 of the valve block 501, such that the chamber 522 of the syringe 524is in fluid communication with the second port 504, while the first port504 is isolated and/or closed from being in fluid communication with thechamber 522 of the syringe 524. In some embodiments, the first port 504is isolated between two circular sealing members 517 when the CO₂delivery device 530 is in the second position. The second port 504 maybe coupled to a connection line (not shown) suitable for delivering CO₂to a subject. When the CO₂ delivery device 530 is engaged in the secondposition, the CO₂ in the chamber 522 of the syringe 520 may be deliveredto the subject.

In accordance with the embodiment as provided herein, a user may holdthe CO₂ delivery device 530 single-handedly by grasping the outersurface of the syringe chamber 522, such that the shuttle valve assembly500 points away from the user and the valve block 516 faces upward. Todeliver one or more boli of CO₂ using the CO₂ delivery device 530, auser may apply a force with their thumb to the valve block 516 againstthe biasing member 506, so as to engage the CO₂ delivery device 530 in asecond position.

As will be appreciated, the CO₂ delivery devices, in accordance with theembodiments described herein, may include tubing lines that arepermanently bonded to the first port and the second port of the shuttlevalve assembly. This allows a user to connect the tubing that leads tothe first port to a CO₂ supply assembly or a CO₂ source. The user mayalso connect the tubing line that leads to the second port directly orindirectly to the subject.

The devices and systems disclosed herein may be pre-purged with CO₂prior to packaging and/or use. As will be appreciated, the CO₂ deliverydevices, in accordance with the embodiments as described herein, may bepurged and/or loaded with CO₂ prior to use. Alternatively or inaddition, in certain embodiments, the CO₂ delivery device may be flushedand/or loaded with CO₂ prior to and/or during packaging. In such anembodiment, a user may open the packaging containing the device andconnect the device to the CO₂ without having to flush and/or load thedevice with CO₂ prior to use. In still other embodiments, the CO₂delivery devices permanently bonded to tubing lines can also bepre-purged with CO₂ prior to packaging and/or use.

Throughout this specification, any reference to “one embodiment,” “anembodiment,” or “the embodiment” means that a particular feature,structure, or characteristic described in connection with thatembodiment is included in at least one embodiment. Thus, the quotedphrases, or variations thereof, as recited throughout thisspecification, are not necessarily all referring to the same embodiment.

Similarly, it should be appreciated that in the above description ofembodiments, various features are sometimes grouped together in a singleembodiment, figure, or description thereof for the purpose ofstreamlining the disclosure. This method of disclosure, however, is notto be interpreted as reflecting an intention that any claim requiresmore features than those expressly recited in that claim. Rather,inventive aspects lie in a combination of fewer than all features of anysingle foregoing disclosed embodiment. It will be apparent to thosehaving skill in the art that changes may be made to the details of theabove-described embodiments without departing from the underlyingprinciples set forth herein.

1. A CO₂ delivery device, comprising: a syringe comprising a chamber;and a shuttle valve assembly comprising a first port and a second port,the shuttle valve assembly in fluid communication with the chamber ofthe syringe; wherein the first port and the chamber are in fluidcommunication and the second port is not in fluid communication with thechamber when the CO₂ delivery device is in a first position, and whereinthe second port and the chamber are in fluid communication and the firstport is not in fluid communication with the chamber when the CO₂delivery device is in a second position.
 2. The CO₂ delivery device ofclaim 1, wherein the first position is independent from the secondposition.
 3. The CO₂ delivery device of claim 1, the shuttle valveassembly further comprising: a valve block; and a valve base, whereinthe valve block comprises at least one opening, and wherein the firstport and the second port are positioned on the valve base.
 4. The CO₂delivery device of claim 1, the shuttle valve assembly furthercomprising: a valve block; and a valve base, wherein the valve basecomprises at least one opening, and wherein the first port and thesecond port are positioned on the valve block.
 5. The CO₂ deliverydevice of claim 3 or 4, the shuttle valve assembly further comprising: abiasing member, wherein the biasing member is disposed between the valveblock and the valve base.
 6. The CO₂ delivery device of claim 5, whereinthe biasing member biases the valve block into the first position whichpermits pressurization of the chamber with CO₂ gas.
 7. The CO₂ deliverydevice of claim 6, wherein when a force is applied against the biasingmember, the valve block is disposed into the second position whichpermits delivery of a bolus of pressurized CO₂ gas from the chamber to apatient.
 8. The CO₂ delivery device of claim 5, wherein the biasingmember biases the valve block into the first position which permitsdelivery of a bolus of pressurized CO₂ gas from the chamber to apatient.
 9. The CO₂ delivery device of claim 1, wherein the syringefurther comprises a threaded plunger, and wherein the syringe isconfigured to receive a threaded plunger.
 10. The CO₂ delivery device ofclaim 1, further comprising: a CO₂ cartridge, wherein the CO₂ source isdirectly coupled to either the first port or the second port.
 11. A CO₂delivery device, comprising: a syringe, comprising a chamber; and aplunger; and a shuttle valve assembly, comprising a valve block havingat least one opening; a valve base having a first port and a secondport; and a biasing member biased against the valve block; wherein thefirst port and the chamber are in fluid communication and the secondport is closed when the CO₂ delivery device is in a first position,wherein the second port and the chamber are in fluid communication andthe first port is closed when the CO₂ delivery device is in a secondposition, and wherein the first position is independent from the secondposition.
 12. The CO₂ delivery device of claim 11, wherein the biasingmember is configured to maintain the CO₂ delivery device in the firstposition absent outside force from a practitioner.
 13. The CO₂ deliverydevice of claim 12, wherein the CO₂ delivery device is disposed in thesecond position when a force is applied against the biasing member. 14.The CO₂ delivery device of claim 11, further comprising: a pressureregulator; and a CO₂ cartridge, wherein the CO₂ cartridge is coupled thepressure regulator, and wherein the pressure regulator is coupled to thefirst port.
 15. The CO₂ delivery device of claim 14, wherein the biasingmember is configured to maintain the CO₂ delivery device in the firstposition such that the chamber is in fluid communication with the CO₂cartridge.
 16. The CO₂ delivery device of claim 15, wherein the CO₂delivery device is disposed in the second position when a force isapplied against the biasing member such that the chamber is in fluidcommunication with the second port for delivery of a bolus of CO₂ to apatient.
 17. The CO₂ delivery device of claim 11, further comprising anCO₂ cartridge, wherein the CO₂ cartridge is coupled to the second portand the biasing member is configured to maintain the shuttle valveassembly in the first position, such that the chamber is in fluidcommunication with the first port, and wherein the CO2 delivery deviceis disposed in the second position when a force is applied against thebiasing member such that the chamber is in fluid communication with theCO₂ cartridge.
 18. A system for introducing CO₂ as a contrast agent to asubject, the system comprising: a CO₂ source; and the CO₂ deliverydevice of claim 1, wherein the CO₂ source is coupled to the CO₂ deliverydevice, and wherein the CO₂ delivery device is coupled to the subject.19. The system of claim 18, the system further comprising a pressureregulator.
 20. The system of claim 19, the system further comprising agas sensor.
 21. The system of claim 20, the system further comprising afilter.
 22. The system of claim 21, further comprising at least onetubing line, wherein the CO₂ source is coupled to the CO₂ deliverydevice with at least one tubing line, and wherein the CO₂ deliverydevice is coupled to the subject with at least one tubing line.
 23. Amethod for delivering CO₂ as a contrast agent to a subject, the methodcomprising: coupling a CO₂ source to a CO₂ delivery device, wherein theCO₂ delivery device is in fluid communication with and receivespressurized CO₂ from the CO₂ source in a first position; coupling theCO₂ delivery device to the subject; actuating the CO₂ delivery devicefrom the first position to a second position against a biasing forcewhich delivers a bolus of CO₂ from the CO₂ delivery device to thesubject; and permitting the biasing force to automatically return theCO₂ delivery device back to the first position.
 24. The method of claim23, wherein the CO₂ delivery device is in fluid communication with theCO₂ source but not the subject when the CO₂ delivery device is engagedin the first position.
 25. The method of claim 24, wherein the CO₂delivery device is in fluid communication with the subject but not theCO₂ source when the CO₂ delivery device is engaged in the secondposition.
 26. The method of claim 23, further comprising purging the CO₂delivery device prior to coupling the CO₂ delivery device to thesubject.